Cotton is the most important textile plant in the world and is one of the most important crops for the
production of oilseed. Because of its worldwide economic importance, new cultivars are constantly being
released in the world. Although great improvements have been achieved through traditional breeding methods,
cotton breeders are facing many problems, i.e., narrow genetic base, inability to use alien genes and difficulty
in breaking gene linkages. Genetic transformations analyses are main tools used by breeders to overcome these
problems. The aim of the study reported in this paper is to determine the effect of age of explant on regeneration
response of apical shoot for tissue culture and gene transfer systems of cotton. This enabled us evaluate it
effects on cotton transformation. The age of explants was observed to have significant effect on shoot tip
elongation. The elongation rates of the three varieties studied were not significantly different from each other
(p = 0.1573) and was observed to be affected by the size of isolated tips. It was observed that if the starting size
of the apex was less than 1 mm, the tips would not grow at all. Insecticidal lectin gene from Allium sativum was
transferred into the transgenic cotton plants via Agrobacterium-mediated transformation using shoot apices as
explants. Putative transgenic plants were confirmed by leaf GUS assay, kanamycin leaf test and molecular
analysis of plantlet.